Development of a memory device including three-dimensionally arranged memory cells has been advanced. For example, a NAND flash memory device includes a plurality of word lines stacked on a source layer and a semiconductor channel penetrating and extending through the plurality of word lines. Each memory cell is disposed at a portion where each word line and the semiconductor channel intersect each other. In such a memory device, it is difficult to detect structural defect in a stacked body due to variations in manufacturing conditions. Improvements in detecting structural defect in a stacked body remain desired.